(568c) Zeolite Membranes On Hollow Fiber Supports

Zeolite membranes have been intensively investigated for the past two decades and shown to have interesting properties in gas permeation and pervaporation (PV). Examples include LTA membranes for dehydration of organics, MFI for organic separations, e.g., butane isomers and xylene isomers, and FAU for carbon dioxide separation and 1, 3-propanediol seaparation. Mitsui Engineering and Shipbuilding Co. Ltd. in Japan developed the first large scale PV plant in 1998 using tubular LTA membranes for dehydration of organic solvents. In 2003 Bussan Nanotech Research Institute Inc., a 100% subsidiary of Mitsui & Co. Ltd. Japan, tested successfully the dehydration of bioethanol in a pilot scale by using LTA membranes for vapor permeation in Brazil. Despite their excellent water/ethanol separation factor and reasonable flux, the critical drawback shared by the two LTA membranes mentioned above is the large diameter of their tubular supports (i.e., 12 and 16 mm, respectively). This large diameter translates into low membrane area per unit volume, which in turn leads to large inefficient modules. It is also highly desirable to increase the reproducibility of zeolite membranes with high performance, so that the module volume can be further reduced.

In this presentation, we will report the preparation of zeolite membranes by the hydrothermal synthesis on hollow fiber supports. We are interested in using hollow fibers as supports, because of their high packing density (membrane surface area/volume ratio >1,000 m2/m3, if the outer diameter is smaller than 4 mm) and thinner wall. The effects of the seeding methods, the seed amounts and the conditions of the hydrothermal synthesis will be discussed.